* Fixes etcd for macos.
The older version of etcd packaged in kubebuilder 2.3.2 for Darwin
throws a stack trace upon attempted startup.
This retrieves the latest version of etcd from coreos and installs
that instead; this works on all OSes.
I removed some redundancy in the Makefile around test dependency
retrieval, too.
* Capture further OS specific test command tweaks.
